1. Field of the Invention
The invention relates generally to electrical connectors, and particularly to an electrical connector with a locking mechanism that assures a combination with a mating electrical connector.
2. Background Art
An electrical connector is a core component used in many electronic systems to connect wiring harnesses. In recent years, electronic systems have grown increasingly complicated. As a consequence, the number of electrical connectors used in some electronic systems has increased, along with the number of wiring harnesses. Some relatively large connectors have also been developed, which may be provided with several dozen terminals or poles. Such connectors may typically include sub housings or sub connectors corresponding to terminals of various types, such as optical fibers and electrical wires for communication and for power.
Connectors are typically manufactured by a connector manufacturer, and thereafter supplied to a harness assembler to attach wiring harnesses thereto. In the process of assembling a female connector, the terminals disposed at an end of the wiring harnesses may be inserted into a housing from a rear side of the housing. The female connector is typically provided with detents, which may be referred to as housing lances, within the housing thereof. When the terminals of the wiring harnesses are inserted into the housing, a portion of the housing lances may be moved upward due to interference with the terminals, and the lances may thereafter “snap” back to engage with notches of the terminals. The TPA (Terminal position Assurance) member is then inserted into the housing, and bridges a gap in the housing to restrict undesirable movement of the housing lances. For example, the TPA member is inserted into the housing from a front side surface of the housing, and thereby the TPA member bridges the gap, restricting the movement of the lances. The resulting female connector, as is a final product, can be combined with a mating connector, i.e., a male connector. Larger connectors typically require a greater force to combine with the mating connector. Accordingly, the larger connectors are generally provided with an insertion-assist mechanism, such as a lever mechanism, in order to reduce a necessary insertion force. The insertion-assist mechanism typically doubles as a connector locking mechanism to assure a reliable connection between connectors.
FIG. 1A illustrates a connector locking mechanism of a conventional female connector. The female connector 1 includes wiring harness 3, which is inserted from a rear surface of the female connector 1. The female connector 1 is about to be connected with a male connector 2 that is mounted on a printed circuit board 5 disposed within a casing 4. The female connector 1 also includes a TPA member 12 disposed at a front surface thereof. Cylindrical protrusions 13 are disposed on both side surfaces of the housing 11, and an roughly inverted-U-shaped lever 14 is pivotally supported by the protrusions 13. The lever 14 stops at a pre-engagement position as shown in FIG. 1. The lever 14 has an arcuate recess 16 configured to fit about a cylindrical boss 15 disposed on an inner surface of a housing of the male connector 2. In connecting mating connectors 1 and 2, the boss 15 comes into contact with a guide portion 16a of the recess 16. Subsequently, by way of rotation of the lever 14 in a direction of arrow A, the boss 15 is completely fitted into the recess 16, so as to combine the female connector 1 with the male connector 2. The lever 14 includes two arms 141 and a beam 142 supported by the two arms 141. A lever locking portion 17 made of a resin material, which has some flexibility, is suspended in proximity to the middle of the beam 142. The lever locking portion 17 has a substantially U-shaped cross section, and elastically supports a detent 17a. The detent 17a can be engaged with an engaging portion 18 disposed on a corresponding portion of the housing 11 at an engagement position, restricting rotational movement of the lever 14. Thus, the fit of the boss 15 into the recess 16 is maintained, and, as a consequence, the connection between the complementary connectors 1 and 2 is assured.
Still referring to FIG. 1A, the lever locking portion 17 of the conventional female connector 1 is configured to be suspended from the beam 142 of the inverted U-shaped lever 14 in order to avoid external impact during conveyance and the like. While the female connector 1 to which the wiring harnesses 3 are attached is conveyed to the next process, and with the lever 14 at the pre-engagement position shown in FIG. 1A, the lever locking portion 17 cannot avoid interference with the attached wiring harnesses 3. Accordingly, the lever locking portion 17 is subject to an excessive force. Over a period of time, the lever locking portion 17 eventually becomes deformed, such that the locking mechanism ceases to function properly. More specifically, as shown in FIG. 1B, the lever locking portion 17 becomes deformed such that a free end of the lever locking portion 17 acquires a gap length g′, which is smaller than an original gap length g. As a consequence, engagement of the detent 17a with the engagement portion 18 of the housing 11 becomes shallow. Thus, even a slight force applied to the lever 14 may undesirably cause disengagement of the detent 17a and the engagement portion 18, thereby allowing the complementary connectors 1 and 2 to become disconnected due to rotating movement of the lever 14.